Abrasives

Ultimately hand sanding achieves the best results prior to painting or varnishing but it can be very time consuming. A good compromise is to use an orbital saner on the large flat areas and hand sand any rounded and convex parts which would be cut away too quickly with a machine.

Choosing the grit

600 grit (and finer) - Used prior to polishing.
400 grit - Used prior to top coat of varnish or enamel on best brightwork
320grit - Used prior to top or second to top coat
240 grit - Used to flatten undercoats and early varnish coats
120 grit - Used to prepare raw timber prior to first primer coats of varnish or paint
80 grit - Used to remove old paint and filler prior to finer sanding
60 grit and coarser - Used for rapid removal of excess filler and for shaping timber


Choosing the abrasive type

Waterproof Paper can be used wet on plastics or previously painted or varnished surfaces. The water helps to lubricate the surface and reduces clogging. It also prevents dust. However it is hard to judge where the paper has fully matted the surface while it is wet and the water will penetrate small screw holes and may take many hours to dry. Waterproof paper can also be used dry.
Typical applications would be for fine finishing of display cabinets, finishing prior to gold leaf or Dutch metal, hand prop finishing, preparation prior to spraying and marine varnishing,

Glass Paper is suitable for the carpentry shop prior to painting and for removal of splinters where a block plane can not be used. Most conveniently supplied on a roll.

Hook and Loop Abrasives are becoming more and more popular. They are quickly attached to hand blocks which are normally supplied with one medium and one very soft side. The lack of waste and speed of sheet changing plus the ease of storage makes this a good versatile choice for the propshop.

Emery Cloth has a blue twill cloth backing and is used in engineering shops for cleaning of rust, surface preparation and fine finishing.

Abrasive Pads are available in four grades from ultrafine for denibbing and keying between paint coats to heavy duty for removal of corrosion on steel and aluminium. They can be used dry or with water. When used with a hose they will clean and prepare in one quick operation.